WAS DRIVING BACK TO MY OFFICE AND ON THE ON RAMP FROM A HIGHWAY TO INTERSTATE 95 SOUTH. I EASED LEFT TO MERGE ONTO THE INTERSTATE GOING ABOUT 45MPH AND INCREASING SPEED WHEN MY STEERING WHEEL PULLED LEFT QUICKLY ON ITS OWN POWER AND STEERED US HEAD ON TOWARDS THE METAL GUARD RAIL IN THE CENTER MEDIAN. I TRIED TO PULL RIGHT BUT THERE WAS RESISTANCE. I NOTICED AN 'UPHIL DECENT FAULT' ON MY DASH JUST BEFORE MY TRUCK STRUCK THE GUARD RAIL. LUCKILY I WAS ABLE TO LAST SECOND PULL THE VEHICLE RIGHT ENOUGH WHERE IT WASN'T A FULL HEAD ON COLLISION AND MY EMPLOYEE IN THE PASSENGER SIDE WAS JUST SORE AFTER THE FACT. I AM CURRENTLY UNDERGOING MEDICAL TESTS FOR BACK, NECK AND SHOULDER NUMBNESS AS WELL AS TENSION HEADACHES . NO AIRBAGS DEPLOYED! FORD SAID ONCE THE BODY IS FIXED WHERE THEY CAN RUN TESTS THEY WILL SEE WHAT CAN BE DONE, BUT I DO NOT FEEL SAFE DRIVING THIS VEHICLE. IT LITERALLY TRIED TO KILL US. THERE WAS ALSO A 'SERVICE ADVANCETRACK' LIGHT ON THE DASH. I PREVIOUSLY HAD THOSE FAULTS AND THE DEALERSHIP SAID IT WAS A WHEEL BEARING THAT THEY NEEDED TO REPLACE. SOMETHING IS GOING ON WITH THESE VEHICLES.